### Erase functionality KF
Kjeld Flarup
Fri, May 5, 2023 9:53 AM

Hi

I have made a system of tubes to connect water hoses. See attachment.

However water will not flow, as the tubes are not hollow. When I connect
the tubes, the difference() used for each part, is not cutting into the
other tubes.

I only see one possible way to do this, which is to use a global
difference. Thus I have to design the whole system, and the copy the

I really need a way to do an erase, which would simplify this a lot.

--
-------------------- Med Liberalistiske Hilsner ----------------------
Civilingeniør, Kjeld Flarup - Mit sind er mere åbent end min tegnebog
Sofienlundvej 6B, 7560 Hjerm, Tlf: 40 29 41 49
Den ikke akademiske hjemmeside for liberalismen - www.liberalismen.dk

Hi I have made a system of tubes to connect water hoses. See attachment. However water will not flow, as the tubes are not hollow. When I connect the tubes, the difference() used for each part, is not cutting into the other tubes. I only see one possible way to do this, which is to use a global difference. Thus I have to design the whole system, and the copy the design in a difference(). I really need a way to do an erase, which would simplify this a lot. -- -------------------- Med Liberalistiske Hilsner ---------------------- Civilingeniør, Kjeld Flarup - Mit sind er mere åbent end min tegnebog Sofienlundvej 6B, 7560 Hjerm, Tlf: 40 29 41 49 Den ikke akademiske hjemmeside for liberalismen - www.liberalismen.dk LH
Lenore Horner
Fri, May 5, 2023 10:05 AM

You need to make the cylinders you are subtracting a smidge taller than what you subtract them from and shift them down half that smidge.  Like so.  (You don't need the use statement for this part at least.)

diameter=25.6/2;
tykkelse=1.5;

baselen=25;

centerhul=10 - 0.1;

module studs(){
studs_d = 25.6/2;
studs_l=30;

``````difference(){
union(){
cylinder(h = studs_l, r1 = studs_d, r2 =studs_d);
translate([0,0,studs_l])
cylinder(h = 4, r1 = studs_d+1, r2 =studs_d);
translate([0,0,studs_l+4])
cylinder(h = 4, r1 = studs_d+1, r2 =studs_d);
translate([0,0,studs_l+8])
cylinder(h = 4, r1 = studs_d+1, r2 =studs_d);
}
translate([0,0,-0.05])cylinder(h = studs_l+12.1, r1 = studs_d-3, r2 =studs_d-3);
``````

}
}

// Tube
translate([-40,0,0])
rotate([0,90,0])
difference(){
cylinder(h = 120, r1 = diameter, r2 =diameter);
translate([0,0,-0.05])cylinder(h = 120.1, r1 = diameter-3, r2 =diameter-3);
}

studs();
translate([40,0,0])
studs();
translate([80,0,0])
rotate([0,90,0])
studs();
translate([-40,0,0])
rotate([0,-90,0])
studs();

Lenore

On May 5, 2023, at 05:53, Kjeld Flarup kjeld.flarup@liberalismen.dk wrote:

You need to make the cylinders you are subtracting a smidge taller than what you subtract them from and shift them down half that smidge. Like so. (You don't need the use statement for this part at least.) diameter=25.6/2; tykkelse=1.5; baselen=25; centerhul=10 - 0.1; module studs(){ studs_d = 25.6/2; studs_l=30; difference(){ union(){ cylinder(h = studs_l, r1 = studs_d, r2 =studs_d); translate([0,0,studs_l]) cylinder(h = 4, r1 = studs_d+1, r2 =studs_d); translate([0,0,studs_l+4]) cylinder(h = 4, r1 = studs_d+1, r2 =studs_d); translate([0,0,studs_l+8]) cylinder(h = 4, r1 = studs_d+1, r2 =studs_d); } translate([0,0,-0.05])cylinder(h = studs_l+12.1, r1 = studs_d-3, r2 =studs_d-3); } } // Tube translate([-40,0,0]) rotate([0,90,0]) difference(){ cylinder(h = 120, r1 = diameter, r2 =diameter); translate([0,0,-0.05])cylinder(h = 120.1, r1 = diameter-3, r2 =diameter-3); } studs(); translate([40,0,0]) studs(); translate([80,0,0]) rotate([0,90,0]) studs(); translate([-40,0,0]) rotate([0,-90,0]) studs(); Lenore > On May 5, 2023, at 05:53, Kjeld Flarup <kjeld.flarup@liberalismen.dk> wrote: > > <slangefordeler.scad> AM
Fri, May 5, 2023 10:22 AM

It appears you are trying to create an assembly from pipes using a module
to create the segments.  There's no way to make that work in base OpenSCAD,
but it is possible using BOSL2, as shown in example 6 for diff():

On Fri, May 5, 2023 at 5:54 AM Kjeld Flarup kjeld.flarup@liberalismen.dk
wrote:

Hi

I have made a system of tubes to connect water hoses. See attachment.

However water will not flow, as the tubes are not hollow. When I connect
the tubes, the difference() used for each part, is not cutting into the
other tubes.

I only see one possible way to do this, which is to use a global
difference. Thus I have to design the whole system, and the copy the

I really need a way to do an erase, which would simplify this a lot.

--
-------------------- Med Liberalistiske Hilsner ----------------------
Civilingeniør, Kjeld Flarup - Mit sind er mere åbent end min tegnebog
Sofienlundvej 6B, 7560 Hjerm, Tlf: 40 29 41 49
Den ikke akademiske hjemmeside for liberalismen - www.liberalismen.dk

To unsubscribe send an email to discuss-leave@lists.openscad.org

It appears you are trying to create an assembly from pipes using a module to create the segments. There's no way to make that work in base OpenSCAD, but it is possible using BOSL2, as shown in example 6 for diff(): https://github.com/revarbat/BOSL2/wiki/attachments.scad#module-diff On Fri, May 5, 2023 at 5:54 AM Kjeld Flarup <kjeld.flarup@liberalismen.dk> wrote: > Hi > > I have made a system of tubes to connect water hoses. See attachment. > > However water will not flow, as the tubes are not hollow. When I connect > the tubes, the difference() used for each part, is not cutting into the > other tubes. > > I only see one possible way to do this, which is to use a global > difference. Thus I have to design the whole system, and the copy the > design in a difference(). > > I really need a way to do an erase, which would simplify this a lot. > > > -- > -------------------- Med Liberalistiske Hilsner ---------------------- > Civilingeniør, Kjeld Flarup - Mit sind er mere åbent end min tegnebog > Sofienlundvej 6B, 7560 Hjerm, Tlf: 40 29 41 49 > Den ikke akademiske hjemmeside for liberalismen - www.liberalismen.dk > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org > PR
Peter Ragosch
Fri, May 5, 2023 10:43 AM

… and you have to cut the shapes of the vertical studs in the
horizontal tube:

diameter=25.6/2;
tykkelse=1.5;

baselen=25;

centerhul=10 - 0.1;

module studs(){
studs_d = 25.6/2;
studs_l=30;

``````difference(){
union(){
cylinder(h = studs_l, r1 = studs_d, r2 =studs_d);
translate([0,0,studs_l])
cylinder(h = 4, r1 = studs_d+1, r2 =studs_d);
translate([0,0,studs_l+4])
cylinder(h = 4, r1 = studs_d+1, r2 =studs_d);
translate([0,0,studs_l+8])
cylinder(h = 4, r1 = studs_d+1, r2 =studs_d);
}
``````

// cylinder for cutting should overlap on both sides
translate([0,0,-1])
cylinder(h = studs_l+12+2, r1 = studs_d-3, r2 =studs_d-3);
}
}

// Tube
difference(){
union(){
// cutting the studs shape too
studs();
translate([40,0,0])
studs();
translate([-40,0,0])
rotate([0,90,0])
cylinder(h = 120, r1 = diameter, r2 =diameter);
}
// cylinder for cutting should overlap on both sides
translate([-92,0,0])
rotate([0,90,0])
cylinder(h = 222, r1 = diameter-3, r2 =diameter-3);
}

translate([80,0,0])
rotate([0,90,0])
studs();
translate([-40,0,0])
rotate([0,-90,0])
studs();

Peter

On Fri, 5 May 2023 06:05:17 -0400
Lenore Horner lenorehorner@sbcglobal.net wrote:

You need to make the cylinders you are subtracting a smidge taller
than what you subtract them from and shift them down half that
smidge.  Like so.  (You don't need the use statement for this part at
least.)

diameter=25.6/2;
tykkelse=1.5;

baselen=25;

centerhul=10 - 0.1;

module studs(){
studs_d = 25.6/2;
studs_l=30;

`````` difference(){
union(){
cylinder(h = studs_l, r1 = studs_d, r2 =studs_d);
translate([0,0,studs_l])
cylinder(h = 4, r1 = studs_d+1, r2 =studs_d);
translate([0,0,studs_l+4])
cylinder(h = 4, r1 = studs_d+1, r2 =studs_d);
translate([0,0,studs_l+8])
cylinder(h = 4, r1 = studs_d+1, r2 =studs_d);
}
translate([0,0,-0.05])cylinder(h = studs_l+12.1, r1 = studs_d-3,
``````

r2 =studs_d-3); }
}

// Tube
translate([-40,0,0])
rotate([0,90,0])
difference(){
cylinder(h = 120, r1 = diameter, r2 =diameter);
translate([0,0,-0.05])cylinder(h = 120.1, r1 = diameter-3, r2
=diameter-3); }

studs();
translate([40,0,0])
studs();
translate([80,0,0])
rotate([0,90,0])
studs();
translate([-40,0,0])
rotate([0,-90,0])
studs();

Lenore

On May 5, 2023, at 05:53, Kjeld Flarup
kjeld.flarup@liberalismen.dk wrote:

To unsubscribe send an email to discuss-leave@lists.openscad.org

… and you have to cut the shapes of the vertical studs in the horizontal tube: use <MCAD/regular_shapes.scad> diameter=25.6/2; tykkelse=1.5; baselen=25; centerhul=10 - 0.1; module studs(){ studs_d = 25.6/2; studs_l=30; difference(){ union(){ cylinder(h = studs_l, r1 = studs_d, r2 =studs_d); translate([0,0,studs_l]) cylinder(h = 4, r1 = studs_d+1, r2 =studs_d); translate([0,0,studs_l+4]) cylinder(h = 4, r1 = studs_d+1, r2 =studs_d); translate([0,0,studs_l+8]) cylinder(h = 4, r1 = studs_d+1, r2 =studs_d); } // cylinder for cutting should overlap on both sides translate([0,0,-1]) cylinder(h = studs_l+12+2, r1 = studs_d-3, r2 =studs_d-3); } } // Tube difference(){ union(){ // cutting the studs shape too studs(); translate([40,0,0]) studs(); translate([-40,0,0]) rotate([0,90,0]) cylinder(h = 120, r1 = diameter, r2 =diameter); } // cylinder for cutting should overlap on both sides translate([-92,0,0]) rotate([0,90,0]) cylinder(h = 222, r1 = diameter-3, r2 =diameter-3); } translate([80,0,0]) rotate([0,90,0]) studs(); translate([-40,0,0]) rotate([0,-90,0]) studs(); Peter On Fri, 5 May 2023 06:05:17 -0400 Lenore Horner <lenorehorner@sbcglobal.net> wrote: > You need to make the cylinders you are subtracting a smidge taller > than what you subtract them from and shift them down half that > smidge. Like so. (You don't need the use statement for this part at > least.) > > diameter=25.6/2; > tykkelse=1.5; > > baselen=25; > > centerhul=10 - 0.1; > > module studs(){ > studs_d = 25.6/2; > studs_l=30; > > difference(){ > union(){ > cylinder(h = studs_l, r1 = studs_d, r2 =studs_d); > translate([0,0,studs_l]) > cylinder(h = 4, r1 = studs_d+1, r2 =studs_d); > translate([0,0,studs_l+4]) > cylinder(h = 4, r1 = studs_d+1, r2 =studs_d); > translate([0,0,studs_l+8]) > cylinder(h = 4, r1 = studs_d+1, r2 =studs_d); > } > translate([0,0,-0.05])cylinder(h = studs_l+12.1, r1 = studs_d-3, > r2 =studs_d-3); } > } > > // Tube > translate([-40,0,0]) > rotate([0,90,0]) > difference(){ > cylinder(h = 120, r1 = diameter, r2 =diameter); > translate([0,0,-0.05])cylinder(h = 120.1, r1 = diameter-3, r2 > =diameter-3); } > > studs(); > translate([40,0,0]) > studs(); > translate([80,0,0]) > rotate([0,90,0]) > studs(); > translate([-40,0,0]) > rotate([0,-90,0]) > studs(); > > Lenore > > > On May 5, 2023, at 05:53, Kjeld Flarup > > <kjeld.flarup@liberalismen.dk> wrote: > > > > <slangefordeler.scad> > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org RW
Raymond West
Sat, May 6, 2023 8:18 PM

A simple method for tubular shapes, is to create the core with
cylinders/whatever, then difference it from a minkowski () copy of the
core and chop off the ends.

something like the following

module inner(){  // shape of core
translate([30,0,0])cylinder(h=30,d=10);
translate([60,0,0])cylinder(h=30,d=10);
rotate([0,90,0]) cylinder(h=100,d=10);
translate([30,0,0])bevel(10,10,3);
translate([60,0,0])bevel(10,10,3);
}

//inner();

module all(){
intersection(){  // trim to size
translate([50,0,-20])
cube(80,true);

difference(){
minkowski(convexity=10){
inner();
sphere(d=3); // make wall ( 1.5)
}
inner();
}
}
}

all();

module bevel(ld,td,th){  // gives a bit iof strength to corners

//ld = long diameter
//td = T off diameter
//th = T height from edge of long piece
hull(){
cylinder(h=th+(ld/2),d=td); // length of T to centre
translate([-td/2-th,0,0])
rotate([0,90,0])
cylinder (h=td+th+th,d=ld);
}
}

On 05/05/2023 10:53, Kjeld Flarup wrote:

Hi

I have made a system of tubes to connect water hoses. See attachment.

However water will not flow, as the tubes are not hollow. When I
connect the tubes, the difference() used for each part, is not cutting
into the other tubes.

I only see one possible way to do this, which is to use a global
difference. Thus I have to design the whole system, and the copy the